performed scRNA-seq with TCR analysis of synovial fluid Tregs (sf Tregs) from JIA patients and identified four Treg clusters: incoming recently-arrived Tregs that expressed CCR7, KLF2, TCF7 and LEF1 (37.24% of sf Tregs); effector Tregs with a dominant suppressive profile that expressed TIGIT, CTLA4, IKZF2, LAYN (31.22% of sf Tregs); effector Tregs with a cytotoxic profile that expressed LGALS1, CXCR6, CCR5, TNFRSF8, GZMA (23.57% of sf Tregs); and GPR56+CD161+CXCL13+Tregs that expressed CXCL13, GPR56, MYO7A, BHLHE40, PTPN13 and KLRB1 (7.96% of sf Tregs) (194). The gene discussed is KLRB1; the disease is juvenile idiopathic arthritis.